Rapid Micro Methods News

Our news pages will keep you informed of press releases and news articles on RMM technologies, updates from technology suppliers, reviews of recent publications and presentations, and what's changing in the world of rapid methods. You can also follow our news posts on Twitter, Facebook, LinkedIn and RSS.

Monday, September 26, 2011

Quidel Corporation, a leading provider of rapid diagnostic testing solutions and cell-based virology assays, announced today that it has received the CE Mark for the Quidel® Molecular hMPV Real-Time RT-PCR Assay. This assay is Quidel's second molecular diagnostic test to receive authorization to market in Europe. This announcement follows the notice of the European launch of Quidel's first molecular diagnostic test -- its RT-PCR test for Influenza A+B on August 5th. Quidel's rapidly expanding menu of molecular diagnostic RT-PCR tests will provide several important benefits to the customer, including enhanced ease of use, reduced processing time, and ready-to-use reagent configurations.

The CE Mark for Quidel's molecular hMPV assay clears the way for the launch of another infectious disease molecular test offering in Europe well in advance of the respiratory disease season. This product is not for sale in the U.S. at this time.

"With the completion of each assay development project, we become even more confident in our ability to execute our pipeline strategy," said Douglas Bryant, president and chief executive officer of Quidel Corporation. "The CE Mark for hMPV is another milestone met, and evidence that we are on track with our molecular diagnostic strategy."

Human metapneumovirus, recently discovered in 2001, infects most children by the time they reach five years of age. It can cause serious respiratory infections, especially in infants, young children, the elderly, and in patients of all ages that are immunocompromised. This disease accounts for about 7% of children admitted to the hospital with respiratory infection. Symptoms of hMPV are very similar to and sometimes indistinguishable from those caused by human respiratory syncytial virus (RSV).

Wednesday, September 21, 2011

IntelligentMDx (IMDx) announced today that it has received CE-Mark for its second automated molecular test for the Abbott FDA cleared m2000 instrument. The IMDx(TM) VanR for Abbott m2000™ test accurately detects and distinguishes the vanA and vanB genes most commonly found in vancomycin-resistant enterococci (VRE) in specimens from patients at risk for colonization or infection. Detection of both the vanA and vanB genes allows for identification of a higher number of at-risk patients than existing tests that only target the vanA gene. Like the recently introduced CE-marked IMDx C. difficile for Abbott m2000 test, the IMDx VanR for Abbott m2000 test offers a high-throughput solution for early detection of pathogens associated with common healthcare-associated infections.

VRE are bacteria which have become resistant to the antibiotic vancomycin, and are responsible for a variety of healthcare-associated infections, including those of surgical wounds, urinary tract, and bloodstream. VRE are transmitted through contact and are most often seen in hospitals due to the high prevalence of contaminated surfaces and hand to hand contact.

The automated nature of the IMDx VanR for Abbott m2000 test allows laboratories to obtain results for up to 48 patient samples in less than 3 hours, and up to 94 patient samples in less than 4 hours. The IMDx VanR for Abbott m2000 test exhibits high sensitivity and specificity when compared to traditional chromogenic agar methods, with values of 96.4% and 98.0%, respectively.

"At IMDx, we have developed unique proprietary software analytic tools, enabling us to produce tests that are sensitive, cost-effective, and rapid alternatives to existing culture-based screening methods for vancomycin-resistant infections. We are proud to offer physicians the ability to make timely, informed decisions about patient care in order to aid in preventing the spread of healthcare-associated infections," says Alice Jacobs, MD, Chairman & CEO of IMDx.

Quotient Bioresearch has recently announced its adoption of Bruker's MALDI Biotyper for bacterial identification, following a successful year-long trial.

The announcement, made at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) (September 17-20, Chicago, US) where Quotient will be presenting a series of posters, places the company in a unique position as the first GLP laboratory to adopt the technology for routine bacterial identification as part of its portfolio of services for antimicrobial development.

Dr Ian Morrissey, Director of Microbiology at Quotient, commented: "Quotient's expert Bioanalytical Sciences team is a fusion of microbiology, immunochemistry and mass-spectrometry specialists, which means we are perfectly placed to embrace this technology."

Delivering rapid and precise identification, Bruker's MALDI Biotyper technology enables Quotient to identify many thousands of organisms a year for antibiotic resistance surveillance, in a much more efficient and accurate manner than traditional identification methods.

Craig Parker, Global Market Manager for Microbiology at Bruker Daltonics, said: "It's great to see Quotient embracing our MALDI Biotyper technology and encompassing it within its own technical work."

Ian added: "The trial period of Bruker's MALDI Biotyper has proved very successful and we are confident that this technology represents the future of bacterial identification, and Quotient is proud to be at the forefront of this exciting field."

Quotient will be presenting two posters on MALDI-TOF technology at ICAAC.

‘D-1285 - Large Scale Performance Evaluation of MALDI-TOF MS in a Central Reference Laboratory Setting' is the largest industry study into MALDI-TOF and ‘D-1284 - Rapid Identification of Veterinary Enterococci by MALDI-TOF MS' analyses how MALDI-TOF technology can aid better identification of bacteria over traditional industry methods.

Quotient Bioresearch is exhibiting at booth number 335 during the conference. Bruker Daltonics is exhibiting at booth number 813.

Tuesday, September 20, 2011

Aegis Food Testing Labs (AFTL), an independent, “a2la” accredited food testing lab, has distinguished itself as the preeminent food safety testing laboratory for isolation and identification of non-O157 Shiga-toxin producing Escherichia coli (STEC). In partnership with a large beef processor, AFTL’s team of Ph.D level microbiologists have gathered critical data allowing them to deliver cost effective rapid screening test results in order for their customers to comply with new USDA compliance standards.

“AFTL’s strong technical capabilities have made them instrumental in the successful implementation of our expanded food safety program” said Craig Letch, Director of Food Safety and Quality Assurance for Beef Products, Inc. “ As part of BPI’s hold and test program, AEGIS onboarded efficient and cost effective rapid detection systems for the “Big Six” non-O157 STEC.”

AFTL has had the opportunity to better understand the dynamics of rapid screening systems with regard to sample enrichment, diagnostic evaluation and data analysis. Rapid screening results for non-O157 STEC relative to product disposition have been analysed according to protocols published in the USDA-FSIS Microbiology Laboratory Guidebook (MLG) Chapter 5B.00, “Detection and Isolation of non-O157 Shiga-Toxin Producing Escherichia coli Strains (STEC) from Meat Products.” Since naturally occurring microorganisms other than the "Big Six" can also contain targets that are detected by the rapid screening tests, yielding what can be classified as “false positive”, it is necessary to conduct cultural confirmation as described in the USDA-FSIS Method 5B.00, which can be an expensive and inefficient process.

The AFTL team has optimized cultural confirmation techniques for the isolation and identification of non-O157 STEC using a series of routine, commercial samples and “spiked” positive control samples. This process has cleared the way for Aegis Food Testing Lab's rapid food testing system to deliver efficient and cost effective solutions that address the new USDA compliance standards.

Monday, September 19, 2011

Accelr8 Technology Corporation announced results presented at the 51st ICAAC held in Chicago on September 17. As previously announced in July, the presenters received an award for an "outstanding presentation of an abstract accepted by ICAAC." The presentation title is "Same-Shift ID Directly from Respiratory Specimens by Automated Microscopy." It reported results from a study using Accelr8's BACcel™ rapid diagnostic system in collaboration with investigators at the Barnes-Jewish Hospital in St. Louis.

The study reported results with 53 bacteria-positive lung specimens from ICU patients. Of these, 16 were positive for the two most common ICU pathogens that can express multi-drug resistance (MDR)--Staphylococcus aureus (the common "Staph") and Pseudomonas aeruginosa. The latter Gram-negative organism is one of the most complex and difficult to treat MDR threats found in hospital-acquired infections.

Accelr8's BACcel™ rapid diagnostic system correctly identified 9/9 S. aureus and 7/7 P. aeruginosa directly from specimen samples. It also correctly identified the lack of these target organisms in the remaining 37 specimens, yielding detection sensitivity and specificity of 100% and 100%, respectively.

ICAAC (www.icaac.org) is the annual Interscience Conference on Antimicrobial Agents and Chemotherapy. Organized by the American Society for Microbiology (www.asm.org), ICAAC is a major global congress for Clinical Microbiology and Infectious Diseases Medicine.

According to David Howson, Accelr8's president, "We are honored by the recognition from ICAAC's review committee. Results in our outside studies continue to strongly support the system's accuracy and speed. The BACcel™ system continues as the only new technology to demonstrate multiple organism quantitative identification with multiple antibiotic resistance detection. The BACcel system stands alone in directly confronting the relentlessly advancing global pandemic of multiple antibiotic resistance."

Accelr8 Technology Corporation is a developer of innovative materials and instrumentation for advanced applications in medical instrumentation, basic research, drug discovery, and bio-detection. Accelr8 is developing a rapid analytical platform for infectious pathogens, the BACcel™ system, based on its innovative surface coatings, assay processing, and detection technologies. In addition, Accelr8 licenses certain of its proprietary technology for use in applications outside of Accelr8's own products.

Nanosphere's NSPH +0.50% Verigene BC-GP test, based on the company's proprietary array-based nanoparticle technology, demonstrated 100% sensitivity and specificity for detection of the drug-resistant bacteria MRSA and VRE, and an overall sensitivity of 98.4% for a broad panel of bacterial targets, according to an initial study.

The study, presented September 18 at the 51st Interscience Conference on Antimicrobial Agents and Chemotherapy (ICAAC) in Chicago was conducted by Dr. Nathan Ledeboer, Dr. Blake Buchan and colleagues at the Medical College of Wisconsin and Dynacare Laboratories in Milwaukee, WI.

Early laboratory identification of pathogenic bacteria in patients with bloodstream infections is critical to managing infections and improving patient outcomes. The benefits of faster diagnosis are well established and include increased survival rates, lower costs of patient care, and reduced use of unnecessary antibiotics. The automated BC-GP test returns results for 13 bacterial identification targets and 3 antibiotic resistance targets in under two and a half hours as compared with current microbiological culture methods that can take 24 -- 48 hours to identify bacterial pathogens and determine their resistance or susceptibility to common antibiotics.

The BC-GP test is part of Nanosphere's growing menu of infectious disease tests for the Verigene(R) platform. The Respiratory Virus Plus Nucleic Acid Test is an FDA-cleared, in vitro diagnostic test for respiratory viruses. Additional sample-to-result tests for gram-negative bacteria, C. difficile, and enteric pathogens are currently in development.

The study abstract, entitled "Evaluation of the Microarray-Based Sample-to-Result Verigene BC-GP Assay for Rapid Detection of Gram-Positive Bacteria and Resistance Determinants Directly from Positive Blood Cultures" can be accessed at http://www.abstractsonline.com/plan/AdvancedSearch.aspx and will be published through ASM Press at the conclusion of the conference.

This test is currently for investigational use only (IUO) and not for clinical diagnostic use; the performance characteristics of the test have not been established. The BC-GP test is currently pending CE-IVD and FDA review and clearance.

Nanosphere is using the power of nanotechnology to create innovative molecular diagnostics for the medical field. The Verigene(R) System is an easy-to-use cartridge-based platform that enables rapid, cost-effective, multiplexed testing in a near-patient setting. Current and forthcoming products include clinical diagnostics in the areas of infectious disease, pharmacogenetics, cardiology, and human genetics.

Thursday, September 15, 2011

Roka Bioscience announced today that the company has initiated the external evaluation process for AOAC certification of the Listeria Detection Assay. This evaluation is the final step required to receive AOAC Research Institute (AOAC-RI) certification of methods used in the food safety industry. The field study is conducted by a third-party laboratory and monitored by AOAC. The internal portion of the evaluation began in July. We expect to complete both the internal and external evaluations in the fourth quarter.

The Listeria Detection Assay runs on the Roka Automated Instrument, an innovative fully automated molecular system for the detection of food pathogens in food and environmental samples. This instrument utilizes a simple three-step procedure--Enrich, Transfer, Automate--and is capable of processing over 300 samples in 8 hours. The instrument's dynamic scalability and high throughput provides greater efficiency, flexibility, and freedom to meet the ever-increasing demands placed on food safety laboratories.

The initial menu for the Roka Automated Instrument will be the Listeria and Salmonella Detection Assays. Upon the completion of the Listeria Detection Assay evaluation, the Salmonella Detection Assay will be submitted for external evaluation. The Salmonella Detection Assay internal and external evaluations will begin in Q4 2011.

Researchers at the University of Sheffield have developed polymers that fluoresce in the presence of bacteria, paving the way for the rapid detection and assessment of wound infection using ultra-violet light.

When contained in a gel and applied to a wound, the level of fluorescence detected will alert clinicians to the severity of infection. The polymers are irreversibly attached to fragments of antibiotics, which bind to either gram negative or gram positive bacteria – both of which cause very serious infections – informing clinicians as to whether to use antibiotics or not, and the most appropriate type of antibiotic treatment to prescribe. The team also found that they could use the same gels to remove the bacteria from infected wounds in tissue engineered human skin.

Professor Sheila MacNeil, an expert in tissue engineering and wound healing, explained: "The polymers incorporate a fluorescent dye and are engineered to recognise and attach to bacteria, collapsing around them as they do so. This change in polymer shape generates a fluorescent signal that we´ve been able to detect using a hand-held UV lamp."

"The availability of these gels would help clinicians and wound care nurses to make rapid, informed decisions about wound management, and help reduce the overuse of antibiotics," added project lead Dr Steve Rimmer.

Currently, determining significant levels of bacterial infection involves swabbing the wound and culturing the swabs in a specialist bacteriology laboratory with results taking several days to be available. The team is confident that its technology can ultimately reduce the detection of bacterial infection to within a few hours, or even less.

The research has already demonstrated that the polymer (PNIPAM), modified with an antibiotic (vancomycin) and containing a fluorescent dye (ethidium bromide), shows a clear fluorescent signal when it encounters gram negative bacteria. Other polymers have been shown to respond to S. aureus, a gram positive bacteria. These advances mean that a hand-held sensor device can now be developed to be used in a clinical setting.

The research is the result of a three-year project which started in 2006, part-funded by the Engineering and Physical Sciences Research Council (EPSRC) and the Defence Science and Technology Laboratory (Dstl) – an agency of the Ministry of Defence, interested in the medical application of the research in battlefield conditions, and a subsequent EPSRC funded PhD studentship.

The team is also investigating whether using a sophisticated technique called fluorescence Non Radiative Energy Transfer (NRET) to generate the light signal could enable a highly refined sensor technology that could have applications in other areas.

"For example, we think that NRET could be very useful in an anti-terrorist and public health capacity, detecting pathogen release or bacterial contamination, whether accidental or deliberate," says Dr Rimmer. "NRET also allows us to learn more about how the polymers collapse around the bacteria, which is important in developing our understanding of how bacteria interact with these novel responsive polymers."

The DMF submissions contain information the Federal Drug Administration (FDA) can review to approve the use of BioVigilant’s equipment in the manufacturing, processing, packaging or storage of drug products. Included in the filings are the test protocols and results of BioVigilant’s extensive testing against the USP<1223> Validation of Alternative Microbiological Methods guideline; environmental, vibration and shock test results; a review of the IMD-A systems’ technology, functionality, subsystems, and operation; and BioVigilant’s IQ/OQ/PQ protocols.

BioVigilant’s IMD-A 300 and IMD-A 350 systems can detect immediately the presence of bacteria in the drug manufacturing process, and in doing so, greatly accelerate the quality assurance processes for drug batch release. In addition, the systems may be used as constant monitors throughout the entire production period in contrast to other equipment which may be used for spot checks.

A laboratory diagnostic kit to diagnose human infections with seasonal influenza viruses and novel influenza A viruses with pandemic potential has been authorized for use by Food and Drug Administration. The in–vitro, or IVD, kit was developed by the Centers for Disease Control and Prevention.

“As the spread of the H1N1 pandemic slowed last year, we conducted an end–to–end review of our nation’s medical countermeasure enterprise, which showed a clear need for better diagnostic tests,” said Dr. Nicole Lurie, assistant secretary for preparedness and response in the U.S. Department of Health and Human Services. “In helping public health officials quickly identify seasonal flu as well as the flu viruses that could become pandemic, this kit can make a real difference in protecting health and saving lives in the United States and around the world.”

The CDC test kit will be given at no cost to qualified international public health laboratories to improve global laboratory capacity for detecting influenza virus infections in human respiratory tract specimens.

The first module is used to identify and distinguish between infection with influenza A and B viruses. The second module can further classify influenza A viruses by subtype, such as H1N1, H3N2 or 2009 H1N1. And the last module specifically detects highly pathogenic avian influenza A (H5N1) virus infection in human respiratory tract specimens, in support of ongoing global preparedness efforts against a possible H5N1 bird flu pandemic.

The modular design makes the kit more efficient for use by diagnostic laboratories, and eliminates waste by allowing users the flexibility to order components separately, according to the laboratory′s needs. “This will lead to more efficient testing, with cost savings for the federal government and for state and local public health agencies,” stated Nancy Cox, P.H.D., director of CDC Influenza Division and director of the World Health Organization Collaborating Center for Surveillance, Epidemiology and Control of Influenza.

The test kit is used with specimens collected from a patient’s upper or lower respiratory tract. Upper respiratory specimens are easily obtainable in an outpatient or inpatient setting, and lower respiratory specimens are typically obtained from severely ill patients with lower respiratory disease (e.g., severe pneumonia) in a hospital setting. The test kit is the only IVD for influenza that is FDA cleared for use with lower respiratory tract specimens. Several studies have shown that among hospitalized patients with severe lower respiratory disease, including critically ill patients requiring mechanical ventilation in the intensive care unit, testing lower–respiratory tract specimens can help detect influenza virus infections that can be missed by only testing upper respiratory tract samples.

Minerva Biolabs GmbH and Mycoplasma Experience Ltd. are proud to organize the first collaborative study of molecular biological mycoplasma detection for cell culture materials and biologicals. This study was strong demanded by customer requests and was requested by the IRPCM Group "Cell Culture" of the International Organisation of Mycoplasmology (IOM).

The aim of the collaborative study is an initial survey on the quality of mycoplasma testing and long term to establish an external quality assurance programme and thus improving the reliability of NAT-based mycoplasma testing. The study will allow each individual laboratory an assessment of the accuracy and sensitivity of the tests carried out in international comparison. The collaborative study is planned in future on a semi-annual basis.

An identical set of samples will be shipped to all participants and independently analyzed under individual conditions. The results are evaluated statistically. All participants receive the evaluation for information about the correctness of the analysis as well as an individual certificate of success, if 4 of 5 samples were analyzed properly. The evaluation is anonymous. The data might be published in respect of relevance and interest at conferences or in print media but not for commercial use.

The mycoplasmas in the sample set will be titrated by Mycoplasma Experience Ltd. applying the culture method (CFU/ml), and by Minerva Biolabs using a qPCR method (GU/ml). The samples set may contain different sample matrices, concentrations and species.

An international consortium of researchers has devised a novel strategy for developing rapid, inexpensive diagnostic tests for microbial infections.

Effective treatment of microbial infection is critically dependent on early diagnosis and identification of the causative organism. One inexpensive, rapid and adaptable to point-of-care diagnostic method is immunoassay for microbial antigens that are shed into bodily fluids during infection. A major barrier to developing these diagnostics is determining which of the hundreds or thousands of antigens produced by the pathogen are actually present in patient samples in detectable amounts.

Using a technique they call In vivo Microbial Antigen Discovery (InMAD),the researchers amplifed the small signals present in an infected mouse's blood by purifying serum samples and using them to immunize another mouse. The resulting "InMAD immune serum" from the second mouse, which contains antibodies specific for the soluble microbial antigens present in sera from the infected mice, is then used to probe blots of bacterial lysates or bacterial proteome arrays.

The spots on the blot or the array that light up indicate the antigens to which the mouse immune system reacted. These are the antigens that could be targeted in an immunoassay.

Using the InMAD system, they successfully identified antigens that could be used in rapid diagnostics for the biothreats Burkholderia pseudomallei and Francisella tularensis.

The research was published in mBio, an open access online journal published by the American Society for Microbiology to make microbiology research broadly accessible.

Thursday, September 1, 2011

Resonetics introduces the RapidX250 laser micromachining system, developed for Universities and Corporate research to fabricate microfluidics, MEMs and medical devices in a rapid prototype fashion with tolerances approaching 1 micron. Traditionally MEMs devices are fabricated by traditional semiconductor lithography but the multi-step process takes significant time. The RapidX250 uses a multi-wavelength excimer laser (193nm and 248nm) to directly fabricate the structures in a single step, drastically reducing prototype time.

Compared with other lasers and methods, the RapidX250 is very flexible, able to micro fabricate 2-D (flat sheets, tubes) and 3-D parts (balloons, non-planar surfaces) , including XYZ, theta and goniometer. At 193nm laser wavelength, the laser can ablate cleanly fluropolymers (such as nylon, pebax, Teflon), bioabsorbable polymers and glass. The system has a quick exchange scheme to allow the user to switch to 248nm laser wavelength, ideal for machining polymers, ceramic and metals (such as stents).

And lastly the RapidX250 was designed to be user friendly with a DXF file-to-CNC converter to quickly convert concepts into prototypes, ideal for a multi-user environment.

Resonetics is the largest total solution provider of laser micromachining products and services in the world. It is also regarded as having the largest independent plastic (polymer) laser micromachining facility with more than 50 UV-based laser micromachining systems and with three clean rooms.

Laser micromachining represents a critical fabrication technology for the manufacturing of medical devices, diagnostics, and a variety of non-medical products as the machining features become increasingly small.

A new type of diagnostic could let hospital laboratories identify the presence of dangerous bacteria up to five times faster than conventional methods. The test could reduce unnecessary antibiotic use and provide more reliable water-quality test results. The key to the process is a membrane with nanosized pores, which enable rapid growth and identification of live organisms.

Current methods of identifying bacterial infections in hospitals seem almost antiquated: Swab, rub on petri dish filled with agar, and wait. Some bacteria can take 48 hours or more to grow into visible colonies. But the new technology, developed by Hubbard, Ohio-based Nanologix, speeds up the process. Bacteria move through the pores of its membrane, and grow there. Then the membrane is plucked off the agar and placed on a staining plate.

"People knew for decades that microcolonies would be present in culture, but there was no way to transfer them or stain them in a way to make them visible," says Nanologix CEO Bret Barnhizer. But the company's technology—"bionanopore" membranes and "bionanofilters"—is sensitive enough to detect a single cell. And when the nanofilter is saturated with antibodies specific to a particular bacteria or virus, it can quickly indicate whether a particular offender is present.

The first test of the Nanologix system has been completed by a group of researchers at the University of Texas Health Sciences Center on a bacterium known as group B streptococcus. Also known as GBS, it can cause feeding, breathing, and other problems in a newborn baby if its mother is infected with it at the time of childbirth. Because of this, most pregnant women are tested for GBS about a month before their due date, with a culture test that yields results in two to three days. If the results are positive, antibiotics can eliminate the infection before the baby is born.

But if a woman arrives at a hospital in labor and has never been tested for GBS, she's assessed for GBS risk and often given large doses of broad-spectrum antibiotics, just in case. Because the risk assessment basically consists of the physician's best guess, some patients who need the antibiotics won't get them, and some who don't need them will.

A study published online this month in the American Journal of Perinatology by the University of Texas researchers shows that the Nanologix test can yield reliable results in as few as four hours. It's not fast enough to prevent antibiotic administration to untested women already in labor, but it's fast enough to know whether their new babies should be monitored for signs of infection. "It would be great to have a faster-turnaround test," says Kristin Brigger, a Houston private-practice obstetrician and gynecologist who was not involved in the research. "For patients in the academic setting, patients without good prenatal care and high risk of preterm labor, it would be really good."

Other, more advanced technology already offers much faster turnaround than the Nanologix plates. Polymerase chain reaction machines can identify infection in as little as 30 minutes, fast enough for use between onset of labor and delivery. But such machines can be pricey, as can the individual tests, and the technology isn't always available in community hospitals. In contrast, the Nanologix test kits cost between $5 and $10, just slightly more than the customary test, and can be done in any hospital lab. Barnhizer says the company also has developed kits that can detect E. coli, salmonella, listeria, and more; Nanologix plans to submit the first test (for GBS and other gram-positive bacteria) to the U.S. Food and Drug Administration later this year, with hopes for approval by the first quarter of 2012.

Nanologix is also working with the U.S. Environmental Protection Agency to develop kits that can be used during outbreaks for faster, more reliable detection of waterborne microorganisms such as E. coli and cryptosporidium. "It's a really good technique, because it shortens a process of 12 to 18 hours to five or six, so we can get an answer about whether our target bacterium is there or not within a day," says Gerard Stelma Jr., a senior microbiologist with the EPA in Cincinnati. Not only are currently available tests slow, he says, but their effectiveness also varies from day to day. "When I saw what they were doing, I thought this is the most novel new method I have seen in a number of years."

Researchers have discovered a faster, cheaper method for the diagnosis of tuberculosis (TB). A major barrier in TB prevention, especially in developing countries, is that diagnosis is slow and costly. Dr Olivier Braissant and his colleagues have developed a method which could potentially decrease the time taken to make a diagnosis. Their method is also cheaper than the current fastest methods. This research has been published in the Society for Applied Microbiology’s Journal of Applied Microbiology.

The bacterium which causes TB is called Mycobacterium tuberculosis and diagnosis of this disease is often done by growing and examining the bacteria in a laboratory. This process is slow and can take up to 57 days.

Faster methods have been developed, but these tend to be very expensive and are, therefore often unavailable in developing countries. Dr Braissant and his colleagues used a microcalorimeter to detect the growth of Mycobacterium tuberculosis. This method proved to be faster than growing the bacteria in the lab and as fast as other more expensive methods (between 5.5 and 12.5 days).

Microcalorimeters, like the one used in this research, measure the heat given off during a chemical, physical or biological process, in this case when the bacteria grow. They convert this tiny temperature rise into an electrical signal which can be amplified and recorded by a computer. This then produces a graphical footprint which is unique to each species of bacteria.

As multiple samples from the same person can be tested at the same time using the microcalorimeter it is also possible to test drug susceptibilities of the bacteria. This is done by measuring the growth of different samples in the presence of different antibiotics: if no growth is detected with one antibiotic, this drug can be used to fight the infection. With the growing resistance of TB to antimicrobials, this is essential.

A further important feature of this method is that it uses readily available, cheap materials. Other fast TB detection methods often use consumables such as fluorescent or radioactive probes, meaning that every individual test comes at a significant cost. This is on top of the initial cost of the equipment, which can be around $39,000 (US). Whilst relatively inexpensive microcalorimeters are commercially available, a recent study1 estimated that a simple calorimeter can be built for around $1000 (US).

Dr Braissant and his team have shown this new method works in a laboratory setting, but this is not necessarily representative of the way it would work in outside world. So the next step is to test their method outside the lab.

"Microcalorimeters have already been shipped to Tanzania and we hope to start a first validation of our approach in the field before the end of the year" Dr Braissant explained.

One third of the world’s population are infected with TB and in 2009 there were 1.7 million deaths from the disease. The highest number of these deaths was in Africa. TB is spread through the air via sneezing, coughing and spitting and it is estimated that every untreated person infects between 10 and 15 people per year. Prompt and affordable diagnosis is therefore essential. This new technique could potentially provide a method for the rapid diagnosis of TB and due to the relatively low cost, it could be used worldwide.